1. Field of the Invention
The present invention relates to combustion aids, preferably used for internal combustion engines, especially internal combustion engines such as gasoline engines and diesel engines of the types used in automobiles, etc.
2. Prior Art
In recent years, extensive efforts have been made toward reducing noxious emissions in exhaust gases, e.g. CO, NOx and incompletely combusted hydrocarbons, and reductions in fuel consumption by internal combustion engines. The prior art approaches have focused mainly on: (1) post-treatment of exhaust gas, (2) improvements in combustion chambers and use of evaporators, (3) control of fuel and ignition systems, and (4) stratified combustion methods, etc. In particular, a totalized system using a microcomputer has been developed to integrate control of fuel feed, ignition, the refluxing rate of the exhaust gas and the like, such control being responsive to the operating parameters of the engine.
With the exception of exhaust gas treatments, the aforementioned prior art techniques all relate to improvements in the combustion state by changing and controlling the physical environment for combustion, to thereby make the combustion more efficient and these approaches envision further provision for cleaning of the exhaust gas. In other words, such prior art approaches do not attempt to both improve combustion and to reduce noxious emissions, except to the extent that the latter follows from the former. Techniques for the post-treatment of exhaust gas, in general, fall into one of two categories: (1) cleaning exhaust gas using a catalyst and (2) recirculating a portion of the exhaust gas to the egine. These techniques provide good results in reducing hydrocarbon, CO and NOx emissions. However, even by these techniques, complete combustion is not achieved so that emission of the aforementioned air pollutants remains at an unacceptably high level.